Find an Equation in Cylindrical Coordinates for the Equation Given $z = 9 x ^ { 2 } + 9 y ^ { 2 } - 2$

Multiple Choice

Find an equation in cylindrical coordinates for the equation given in rectangular coordinates. $z = 9 x ^ { 2 } + 9 y ^ { 2 } - 2$

A) $z = 9 r + 2$
B) $z = 9 r ^ { 2 } - 2$
C) $z ^ { 2 } = 9 r - 2$
D) $z = \frac { 9 } { 2 } r ^ { 2 } + 2$
E) $z = \frac { 9 } { 2 } r ^ { 2 } - 2$